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the fallacious deductions of our reason； which is slow in
its operations； appears not； in any degree； during the first
years of infancy； and at best is； in every age and period of
human life； extremely liable to error and mistake。 It is
more conformable to the ordinary wisdom of nature to secure
so necessary an act of the mind； by some instinct or
mechanical tendency； which may be infallible in its
operations； may discover itself at the first appearance of
life and thought； and may be independent of all the laboured
deductions of the understanding。 As nature has taught us the
use of our limbs； without giving us the knowledge of the
muscles and nerves； by which they are actuated； so has she
implanted in us an instinct； which carries forward the
thought in a correspondent course to that which she has
established among external objects； though we are ignorant
of those powers and forces； on which this regular course and
succession of objects totally depends。
* * * *
SECTION VI。
Of Probability。＇14＇
T/HOUGH there be no such thing as Chance in the world；
our ignorance of the real cause of any event has the same
influence on the understanding； and begets a like species of
belief or opinion。
There is certainly a probability； which arises from a
superiority of chances on any side； and according as this
superiority increases； and surpasses the opposite chances；
the probability receives a proportionable increase； and
begets still a higher degree of belief or assent to that
side； in which we discover the superiority。 If a dye were
marked with one figure or number of spots on four sides； and
with another figure or number of spots on the two remaining
sides； it would be more probable； that the former would turn
up than the latter； though； if it had a thousand sides
marked in the same manner； and only one side different； the
probability would be much higher； and our belief or
expectation of the event more steady and secure。 This
process of the thought or reasoning may seem trivial and
obvious； but to those who consider it more narrowly； it may；
perhaps； afford matter for curious speculation。
It seems evident； that； when the mind looks forward to
discover the event； which may result from the throw of such
a dye； it considers the turning up of each particular side
as alike probable； and this is the very nature of chance； to
render all the particular events； comprehended in it；
entirely equal。 But finding a greater number of sides concur
in the one event than in the other； the mind is carried more
frequently to that event； and meets it oftener； in revolving
the various possibilities or chances； on which the ultimate
result depends。 This concurrence of several views in one
particular event begets immediately； by an inexplicable
contrivance of nature； the sentiment of belief； and gives
that event the advantage over its antagonist； which is
supported by a smaller number of views； and recurs less
frequently to the mind。 If we allow； that belief is nothing
but a firmer and stronger conception of an object than what
attends the mere fictions of the imagination； this operation
may； perhaps； in some measure； be accounted for。 The
concurrence of these several views or glimpses imprints the
idea more strongly on the imagination； gives it superior
force and vigour； renders its influence on the passions and
affections more sensible； and in a word； begets that
reliance or security； which constitutes the nature of belief
and opinion。
The case is the same with the probability of causes； as
with that of chance。 There are some causes； which are
entirely uniform and constant in producing a particular
effect； and no instance has ever yet been found of any
failure or irregularity in their operation。 Fire has always
burned； and water suffocated every human creature： The
production of motion by impulse and gravity is an universal
law； which has hitherto admitted of no exception。 But there
are other causes； which have been found more irregular and
uncertain； nor has rhubarb always proved a purge； or opium a
soporific to every one； who has taken these medicines。 It is
true； when any cause fails of producing its usual effect；
philosophers ascribe not this to any irregularity in nature；
but suppose； that some secret causes； in the particular
structure of parts； have prevented the operation。 Our
reasonings； however； and conclusions concerning the event
are the same as if this principle had no place。 Being
determined by custom to transfer the past to the future； in
all our inferences； where the past has been entirely regular
and uniform； we expect the event with the greatest
assurance； and leave no room for any contrary supposition。
But where different effects have been found to follow from
causes； which are to exactly similar； all these
various effects must occur to the mind in transferring the
past to the future； and enter into our consideration； when
we determine the probability of the event。 Though we give
the preference to that which has been found most usual； and
believe that this effect will exist； we must not overlook
the other effects； but must assign to each of them a
particular weight and authority； in proportion as we have
found it to be more or less frequent。 It is more probable；
in almost every country of E/UROPE； that there will be
frost sometime in J/ANUARY； than that the weather will
continue open through out that whole month； though this
probability varies according to the different climates； and
approaches to a certainty in the more northern kingdoms。
Here then it seems evident； that； when we transfer the past
to the future； in order to determine the effect； which will
result from any cause； we transfer all the different events；
in the same proportion as they have appeared in the past；
and conceive one to have existed a hundred times； for
instance； another ten times； and another once。 As a great
number of views do here concur in one event； they fortify
and confirm it to the imagination； beget that sentiment
which we call ； and give its object the preference
above the contrary event； which is not supported by an equal
number of experiments； and recurs not so frequently to the
thought in transferring the past to the future。 Let any one
try to account for this operation of the mind upon any of
the received systems of philosophy； and he will be sensible
of the difficulty。 For my part； I shall think it sufficient；
if the present hints excite the curiosity of philosophers；
and make them sensible how defective all common theories are
in treating of such curious and such sublime subjects。
* * * *
SECTION VII。
Of the Idea of Necessary Connexion。
PART I。
T/HE great advantage of the mathematical sciences
above the moral consists in this； that the ideas of the
former； being sensible； are always clear and determinate；
the smallest distinction between them is immediately
perceptible； and the same terms are still expressive of the
same ideas； without ambiguity or variation。 An oval is never
mistaken for a circle； nor an hyperbola for an ellipsis。 The
isosceles and scalenum are distinguished by boundaries more
exact than vice and virtue； right and wrong。 If any term be
defined in geometry； the mind readily； of itself；
substitutes； on all occasions； the definition for the term
defined： Or even when no definition is employed； the object
itself may be presented to the senses； and by that means be
steadily and clearly apprehended。 But the finer sentiments
of the mind； the operations of the understanding； the
various agitations of the passions； though really in
themselves distinct； easily escape us； when surveyed by
reflection； nor is it in our power to recall the original
object； as often as we have occasion to contemplate it。
Ambiguity； by this means； is gradually introduced into our
reasonings： Similar objects are readily taken to be the
same： And the conclusion becomes at last very wide of the
premises。
One may safely； however； affirm； that； if we consider
these sciences in a proper light； their advantages and
disadvantages nearly compensate each other； and reduce both
of them to a state of equality。 If the mind； with greater
facility； retains the ideas of geometry clear and
determinate； it must carry on a much longer and more
intricate chain of reasoning； and compare ideas much wider
of each other； in order to reach the abstruser truths of
that science。 And if moral ideas are apt； without extreme
care； to fall into obscurity and confusion； the inferences
are always much shorter in these disquisitions； and the
intermediate steps； which lead to the conclusion； much fewer
than in the sciences which treat of quantity and number。 In
reality； there is scarcely a proposition in E/UCLID so
simple； as not to consist of more parts； than are to be
found in any moral reasoning which run